1. Field of the Invention
This invention relates to the field of resonant ultrasound spectroscopy (RUS) and more particularly to the use of RUS for correcting or validating finite element models; developing initial testing criteria; initial testing of production parts; and use of archival resonant frequency records for subsequent testing of parts during maintenance procedures.
2. The Prior Art
Resonant ultrasound testing is known in the prior art as exemplified by U.S. Pat. Nos. 4,976,148 Migliori et al., 5,062,296 Migliori et al., 5,351,543 Migliori et al., 5,355,731 Dixon et al., 5,495,763 Rhodes et al., 5,408,880 Rhodes et al., and 5,425,272 Rhodes et al.
U.S. Pat. No. 5,355,731 teaches measurement of sphericity utilizing resonant ultrasound spectroscopy. In this disclosure, a first set of calculations are used to determine resonant frequencies as the functions of Poisson's ratio where the spherical objects have an ideal dimension. Next, calculations are made to determine a set of resonant frequencies where there is a deviation from dimensions of the ideal object dimensions. Then a production object is measured by resonant ultrasound (RUS), and is compared to the calculated values to determine the deviation from the ideal object dimensions.
Migliori U.S. Pat. No. 4,976,148 teaches the use of resonant ultrasound spectroscopy (RUS) for determination of elastic constants of a sample.